Abstract

Bacteria play a crucial role in regulating biogeochemical cycles in peatlands. Most of the studies on soil bacteria focus mainly on the peat surface and bacteria that exist in the deeper peat layers are still poorly known in tropical areas. This study was conducted to examine bacterial abundances along the peat depths in peat forest ecosystems (peat swamp forest (PSF) and logged-over secondary forest (LOF)) and an oil palm plantation (7.5 years after planting (7.5 YAP OPP)) at intervals of 0–30 cm, 30–40 cm, 40–50 cm, and 50–60 cm. Isolation of bacteria from peat samples was carried out on several selective and non-selective media. Bacteria identification was conducted by amplifying the 16S rRNA gene. The result showed that the same dominant bacterial taxa were found with different abundances in all study sites which were Proteobacteria, Firmicutes, and Actinobacteria. Vertical stratification of Proteobacteria and Firmicutes was observed along the depths, might due to the fluctuations of water table in the peatland mainly in 7.5 YAP OPP. Richness was highest at 0–30 cm in LOF and 7.5 YAP OPP, while PSF at 30–40 cm. This study suggests that deeper peat depth supports the bacterial growth and environmental conditions related to water table level influenced the bacterial abundances.

中文翻译：

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森林生态系统和油棕人工林泥炭土壤中的细菌多样性

摘要

细菌在调节泥炭地生物地球化学循环中起着至关重要的作用。关于土壤细菌的大多数研究主要集中在泥炭表面，而在热带地区，在较深的泥炭层中存在的细菌仍然鲜为人知。进行这项研究的目的是为了研究泥炭森林生态系统（泥沼森林（PSF）和砍伐的次生林（LOF））和油棕人工林（种植后7.5年（7.5 YAP OPP））沿泥炭深度的细菌丰度。间隔为0–30 cm，30–40 cm，40–50 cm和50–60 cm。从泥炭样品中分离细菌是在几种选择性和非选择性培养基上进行的。通过扩增16S rRNA基因进行细菌鉴定。结果表明，在所有研究地点（即变形杆菌）中，都发现了相同的优势细菌类群，其丰度不同，硬毛菌和放线菌。沿深度观察到了细菌和菌丝的垂直分层，这可能是由于泥炭地的地下水位波动主要在7.5 YAP OPP中引起的。LOF和7.5 YAP OPP的丰富度最高，为0–30 cm，PSF为30–40 cm时，丰富度最高。这项研究表明，更深的泥炭深度支持细菌的生长，而与地下水位相关的环境条件会影响细菌的丰度。